Cut v0.13.0-rc.0

Signed-off-by: Bartlomiej Plotka <bwplotka@gmail.com>

CHANGELOG.md

@@ -11,6 +11,8 @@ We use *breaking* word for marking changes that are not backward compatible (rel
 
 ## Unreleased
 
+## [v0.13.0-rc.0](https://github.com/thanos-io/thanos/releases/tag/v0.13.0-rc.0) - 2020.05.19
+
 ### Fixed
 
 - [#2536](https://github.com/thanos-io/thanos/pull/2536) minio-go: Fixed AWS STS endpoint url to https for Web Identity providers on AWS EKS

VERSION

@@ -1 +1 @@
-0.12.2
+0.13.0

docs/release-process.md

@@ -65,6 +65,8 @@ Release is happening on separate `release-<major>.<minor>` branch.
 
   For release candidate just reuse same branch and rebase it on every candidate until the actual release happens.
 
+1. Create small PR to master (!) to cut CHANGELOG. This helps to maintain new changelog on master. E.g: 
+
 1. Update [CHANGELOG file](/CHANGELOG.md)
 
   Note that `CHANGELOG.md` should only document changes relevant to users of Thanos, including external API changes, performance improvements, and new features. Do not document changes of internal interfaces, code refactorings and clean-ups, changes to the build process, etc. People interested in these are asked to refer to the git history.
@@ -74,14 +76,17 @@ Release is happening on separate `release-<major>.<minor>` branch.
   what have changed between release candidates.
 
 1. Double check backward compatibility:
+
     1. *In case of version after `v1+.y.z`*, double check if none of the changes break API compatibility. This should be done in PR review process, but double check is good to have.
     1. In case of `v0.y.z`, document all incompatibilities in changelog.
 
 1. Double check metric changes:
+
     1. Note any changes in the changelog
     1. If there were any changes then update the relevant alerting rules and/or dashboards since `thanos-mixin` is part of the repository now
 
 1. Update tutorials:
+
     1. Update the Thanos version used in the [tutorials](../tutorials) manifests.
     1. In case of any breaking changes or necessary updates adjust the manifests
        so the tutorial stays up to date.